Is it ok to build a wall not on main's, but on natural's choke?

I play Terran and in 1v1 most of the time I wall up aganist Protoss and Zerg. Recently it came to my mind that instead of building a wall on main's choke I can build it at natural's, thus protecting them both. Of course, this is not applicable to all maps, but, for example, on Blistering Sands building wall and concentrating units on natural's choke seems a good idea to me, because 1) I better protect the natural 2) My units are concentrated closer to the enemy 3) I can quickly intercept the force that is trying to destroy rocks at backdoor.

Are there any disadvantages to this tactic? I can think only of one: in case of drop it's farther for my units to run. But given that I usually try to detect and intercept/anticipate drops, it doesn't seem to be a big problem.

Solution 1:

Let's talk about the rise and the fall of the 2Gate strategy, because I think that discussion will enlighten you as to the strengths and weaknesses of blocking as the entrance of the natural.

The Rise

The 2 Gate strategy was developed near the end of the Beta, largely by a player known as Tester. Tester's strategy revolved around using the two Gateways at the entrance to the natural into early pressure. This was a reaction to many Zerg players at the time going for more Zergling centric builds after a series of Roach nerfs.

Strengths

By placing the Gateways in a "wall" he could stop any counter pressure from Zerglings, allowing him to take an early expo and possibly deny the Zerg player's expansion (putting him a base ahead). Since Zerg usually rely on base advantage this was a very strong build. What's more by using warp technology he could warp in units outside of his wall while using a single Photo Cannon to stop any Roach pressure (as even at max range the Photon cannon could reach the Roaches if they attacked the wall).

Thus Tester would have a safe, early expansion.

The Fall

So why don't more Protoss go for 2 Gate pressure against Zerg? Well partially nerfs to Zealot production mean that Protoss couldn't apply pressure as affectively, but a recent change to Roach range really cut down the effectiveness of walling in. Because Roaches now have a range of 4, they are capable of attacking the Protoss wall without taking Photon Cannon fire. As a result building a wall at your natural suffers from exposing your production facilities to harassment, while blocking off your own ability to quickly reinforce from your front to your main. This is the same problem as walling off at your main.

The Future

Does walling have a future? Well a discussion of the history and its roll in the meta game (and why the Roach range buff was so important to Zerg players) is very important so that you understand how these factors contribute; however, that doesn't mean you can't. Walling at the natural provides for the same buffer against early Zergling pressure, and is useful to 1 Gate Expand, style builds. Additionally, Terran players can use the ability to lift off to remove the exposure latter in the game when the wall stops being beneficial.

Do I think that walling at the natural has a place? Yes. Do I think it'll become standard? Based on the disadvantages I've listed, probably not. I think its definitely something you should explore and that it'll come back again in a serious way.

Solution 2:

Here's my experience being on the other end of it as Zerg going early roaches.

Against Terran I often have trouble breaking through a wall at the main, but the choke at the natural is usually slightly bigger and thus harder to finish, as well as I usually find the army that's defending to be slightly smaller if they went for the wall at the natural. This could mostly be from the command center for the fast expand though, as I don't think people wall off their natural if they don't plan to fast expand.

Another reason that the choke at the natural always seems easier to break for me is that I'm not trying to fight up a narrow ramp. On the ramp, I need to get on the ramp to gain vision of the supply depots. If I'm on the ramp then marauders can hit me while I'm hitting the supply depot and roaches don't like marauders one bit. If it's the choke at the natural though, with the new roach range upgrade in the recent patch, I can safely attack the supply depot without being in danger of being sniped by marauders.

To be sure though if there's no early pressure it definitely works pretty well and I did use to have trouble with it when I was playing more passively and went for a later attack.